1. Field
The exemplary embodiments disclosed in the present disclosure relate to a holographic display apparatus and a holographic display method, and more particularly, to a holographic display apparatus and a holographic display method capable of preventing binocular crosstalk while providing hologram images having different viewpoints to the left and right eyes of an observer.
2. Description of the Related Art
As methods of realizing 3D images, methods which use glasses (also referred to as “glasses methods”) and methods which do not use glasses (also referred to as “non-glasses methods”) are widely used. Examples of the glasses methods include deflected glasses methods and shutter glasses methods, and examples of the non-glasses methods include lenticular methods and parallax barrier methods. Such methods use binocular parallax and are limited in increasing the number of viewpoints. In addition to this, these methods make viewers feel tired due to the difference between the depth of images, which the brain perceives, and the focus of the eyes.
Recently, holographic display methods, which are 3D image display methods capable of making the depth, which the brain perceives, consistent with the focus of the eyes and providing full parallax, have been gradually put to practical use. A holographic display technique uses a principle that once reference light is irradiated onto a hologram pattern having recorded thereon an interference pattern obtained by interference between object light reflected from an original object and the reference light, the reference light is diffracted, and an image of the original object is reproduced. A currently commercialized holographic display technique provides a computer-generated hologram (CGH), rather than the hologram pattern obtained by directly exposing the original object to light, as an electric signal to a spatial light modulator. The spatial light modulator forms the hologram pattern and diffracts incident light according to the input CGH signal, thereby generating a 3D image.
However, a very high resolution spatial light modulator and a very large amount of data processing are required to implement a perfect holographic display technique. Recently, to reduce the amount of data processing required to be performed while still achieving a sufficient resolution, a binocular hologram technique of providing hologram images to only a viewing zone corresponding to both eyes of the observer has been proposed. For example, a hologram image having a viewpoint corresponding to a left-eye viewing zone of the observer and a hologram image having a viewpoint corresponding to a right-eye viewing zone of the observer are generated and provided to the left and right eyes of the observer, respectively. In this case, no hologram image for other viewpoints is generated, and thus, a data processing amount may be greatly reduced, and a currently commercialized display apparatus may satisfy a resolution condition of the spatial light modulator.